1. Technical Field
The present invention relates generally to hole saws and, more particularly, to a structure and method for coupling a hole saw and pilot bit to a drill.
2. Discussion
A hole saw is a drill accessory that allows a user to make circular cut-outs in a material such as wood, steel, fiberglass, plastic, etc. Hole saws generally range in size from five-eighths of an inch to six inches in diameter. The main components of conventional hole saws include, as best illustrated in FIG. 1, a saw 10, an arbor 12, and a pilot bit 14. The saw commonly includes a threaded aperture 16 and a plurality of mounting holes 18 formed in the closed end 20 of the saw. The arbor includes a post 22 that is threaded to cooperate with aperture 16 to releasably couple the arbor to the saw. The arbor further includes pins 24 that are disposable within the mounting holes 18 to prevent the saw from unscrewing off the threaded post 22. The pilot bit is disposable within a cavity in the threaded post, is held in place by a set screw 26 and protrudes from the cutting edge of the saw to guide the saw during cutting. Finally, the arbor includes a shank 28 that is connectable to a drill or driver and that in many configurations is non-circular or hex-shaped in cross-section.
While the above-described hole saw assembly and similar arrangements in the art have proven to operate in a generally satisfactory manner, numerous areas for improvement exist. For example, due to the relative positioning and sizes of the threaded post and mounting pins, conventional hole saw arbors are specifically designed for use with hole saws having diameters between either five-eighths of an inch to one and three-sixteenths inches or, on the other hand, for diameters between one and one-quarter inches to about six inches. The different arbor configurations require consumers to purchase and stock additional tools as well as increase the general complexity of using such products. Further, the multiple steps and movement of the plurality of parts required to couple and uncouple the arbor to the hole saw as well as the additional tools needed to connect and disconnect the hole saw and/or pilot bit to the arbor make it difficult and time consuming to remove plugs of cut material from the hole saw as well as to replace the pilot bit. Additionally, when coupling the arbor to the hole saw, the post 22 is threaded into the aperture 16 and hand tightened. The hole saw is then rotated slightly in the opposite direction to align the mounting holes 18 with pins 24. The backing-off of the threaded engagement imparts some play in the connection that can result in increased thread wear, elongation of the mounting holes, and chatter during operation of the hole saw.
In view of the above, it would be desirable to provide a hole saw and arbor configuration that allows the arbor to be easily and efficiently coupled to the hole saw, allows the use of a common arbor for a broader range of hole saw sizes, provides for simple connection of the pilot bit to the arbor, permits the operator to efficiently discharge a plug from the hole saw, and that results in a secure connection of the arbor to the hole saw in order to eliminate chatter and wear. These and other benefits are provided by the present invention as is the simplified method of attaching the arbor to the hole saw and/or pilot bit as hereinafter described.
Accordingly, it is an object of the present invention to provide a hole saw assembly wherein the arbor may be easily coupled to and decoupled from the hole saw.
It is a further object of the present invention to provide a hole saw assembly wherein an operator can connect and disconnect a pilot bit to the arbor with ease and without the use of additional tools.
It is another object of the present invention to provide a hole saw assembly wherein an operator can connect and disconnect the arbor from the hole saw and the pilot bit through selective displacement of a selector sleeve relative to an arbor body between a neutral position, a first operative position, and a second operative position.
Still another object of the present invention is to provide a structure and method for efficiently discharging a plug from a hole saw.
Yet another object of the present invention is to provide an arbor for a hole saw assembly wherein the arbor includes a bit retention assembly and a coupling assembly which are automatically biased into their respective locked and engaged modes to connect the arbor to a pilot bit and hole saw, respectively.
In accordance with the above, one embodiment of the present invention includes an arbor for coupling a hole saw to a drill wherein the arbor includes a body having a coupling end, a shank opposite the coupling end, and a receiving slot proximate to the coupling end. The receiving slot is adapted to receive a mounting tab of the hole saw to couple the hole saw to the adapter body. The arbor also includes a selector sleeve slidably coupled to the body for movement between a first operative position allowing the receiving slot to receive the hole saw tab and a neutral position wherein the selector sleeve prevents removal of the hole saw mounting tab from the receiving slot. The invention also includes a method for coupling an arbor to a hole saw that includes the steps of axially aligning the arbor with the hole saw, axially displacing the arbor relative to the hole saw, and rotating the arbor relative to the hole saw. The present invention also provides an adapter for adapting a conventional hole saw for use with the arbor of the present invention.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood however that the detailed description and specific examples, while indicating preferred embodiments of the invention are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the following detailed description.